Terminal plug for shade rollers



Jan. 30, 1968 J. A. ANDERSON TERMINAL PLUG FOR SHADE ROLLERS Filed Oct.21, 1965 .M 2 y arm m4 II I. 2/ 27M 4 a M. X Z B ATTORNEYS United StatesPatent 0 3,366,160 TERMINAL PLUG FOR SHADE ROLLERS James A. Anderson,Muskegon, Mich., assignor to Brenem'an, Inc., a corporation of OhioFiled Oct. 21, 1965, Ser. No. 500,406 8 Claims. (Cl. 160-323) ABSTRACTOF THE DISCLOSURE A terminal plug for insertion into the open end of atubular shade roller, in which such terminal plug is provided with anannular band seatable along the length of the plug to effectivelydetermine the extent of telescoping engagement of the plug within thetubular roller by abutting the end of the roller. The annular band has afiat internal periphery at least in part, the edges of which definesquared corners, and the terminal plug has annular grooves along itslength for engaging the band by its squared corners. Two embodiments ofthe band are disclosed, one being of elastomeric material, preferablyfor use with a wooden terminal plug, and the other being a split ring ofmoldable plastic material, preferably for use with a molded plasticterminal plug. Either form of terminal plug has a shoulder at itsforward end for retaining the annular stop ring on the plug andpreventing it from being forced over the forward end thereof; in thecase of the wooden plug, the shoulder is a sheet metal cap having aradial lip extending rearwardly of the plug at an acute angle and havinga length sufiicient to engage the band outwardly of its mean diameterwhen the band is forced against it, for positive retention of the bandunder such conditions.

This invention relates to roller assemblies for window shades and thelike, and more particularly to a removable terminal plug for use at oneend of such a roller which provides a series of positively indexed,adjustable positions between the plug and the shade roller which varythe elfective length of the roller assembly in predetermined anddefinite increments which are not disturbed by the application of forcesto the end of the roller which exceed those normally expected in typicalshade operation, such as may arise when the roller is dropped directlyupon its end.

For some time it has been the usual practice of the shade rollerindustry to produce window shades and rollers in several standardlengths, which are chosen to fit a group of window widths which havebeen selected as those most frequently encountered in buildingconstruction. This produces a troublesome and ever-present problem,since in actual practice a great many windows are not of a standarddimension. Further, even where windows are nominally of one of thestandard sizes, the

shade mounting brackets which have been installed very often are spaceda distance that is either slightly greater than or slightly less thanthe exact standard dimension of the shade roller. Thus, actualexperience has proven that more often than not, adjustments in theeffective overall length of a roller must be made before the shade canbe mounted to the actual width of a particular window.

The dealer from which the shade is purchased usually makes theadjustment in its length by selecting the next larger standard size ofshade which he has in stock, and trimming both the shade and the rollerto the required dimension. The dealers are usually equipped with specialtrimming machines for this operation, but there are many possiblesources of human error between the measurement and the trimming of theroller, and it frequently occurs that the final resulting shade rollerdoes not in fact accurately fit the window for which it was intended,and instead has been cut a small amount short of the precise size whichis needed. Further, it also frequently occurs that the casementmeasurements of particular windows which appear upon casual examinationand measurement to be of a standard size are in actuality a small amountwider than the apparent nominal standard dimension. In all of theseinstances, it is necessary for the consumer himself to somehow slightlyadjust the length of the roller to meet the exact circumstances which heencounters when he attempts to mount it for use. Thus, in order toprovide for a completely satisfactory installation, shade rollers shouldbe produced with a structure which allows the overall length to easilybe extended or reduced over a relatively small range, so that the lengthof the roller may be adjusted accordingly.

One type of structure which 'in general has provided satisfactory shaderoller length adjustment is a removable terminal plug which fits intothe gudgeon pin end of the roller. Such a plug may be removed to permittrimming of the roller when this is required, and the plug also providesfor length adjustment of the overall roller assembly if the extent towhich the plug is inserted in the end of the roller may be varied whendesired. Various schemes have previously been suggested for varying theengagement of the plug within the roller and for securing the plugrelative to the roller at various degrees of insertion, since the plugand roller definitely must be relatively secure at various adjustedpositions if continuous satisfactory performance is to be provided.However, most such previous schemes have had inherent limitation whichadversely aifected their operation.

For example, when placed in an extended position, many such plugs tendin operation to slip backward into the roller, and even a small amountof such slippage soon allows the entire roller assembly to drop out ofits mounting brackets. Also, the adjustment of a plug within the rolleris frequently difficult to accomplish or extremely tedious andpainstaking. Further, experience indicates that shade rollers are ofteninadvertently dropped upon one end, typically the plug end. This createsan extremely annoying problem, since in the case of most removableterminal plugs the plug is forcibly driven completely within the end ofthe shade roller tube in which it is inserted. The result is that theterminal plug is made ditficult or impossible to remove from the roller,since it becomes tightly wedged therein in a position which is notaccessible from outside the roller. While the roller tube itself is notoften damaged merely by dropping the assembly in this manner, the tubeis likely to become damaged by either the forcible insertion of the plugthereinto, or else by attempts at removing the plug. This is also likelyto damage the plug, since the gudgeon pin may be pulled from it or elsestructural damage to the pin or the plug may be caused by probing at itorbpulling it in attempting to remove it from the roller tu e.

It is a major object of the present invention to provide a removableterminal plug for shade rollers which effectively resolves the problemsindicated above. The shade roller assembly in which the present terminalplug is used may be quickly and easily adjusted in length by a series ofdefinite incremental adjustments. More importantly however, each of theadjusted positions of the roller assembly is positive and is indexedagainst any subsequent inadvertent changes, whether these result fromnormal operating forces applied to the roller, or from unusual orunexpected forces, such as result when the roller assembly is droppedupon one end.

The foregoing major objectives and the advantages provided thereby,together with numerous other objects and advantages, will be understoodby those skilled in the shade roller and shade equipment art uponfurther consideration of the ensuing specification and its appendedclaims, particularly when taken in conjunction with the accompanyingillustrative drawings setting forth preferred embodiments of theinvention.

In the drawings:

FIG. 1 is a side elevational view, partially in section, of a firstembodiment of the terminal plug of the invention;

FIG. 2 is an enlarged, fragmentary, central section of a portion of thedevice of FIG. 1 showing details thereof;

FIG. 3 is an enlarged, fragmentary, central section of the embodiment ofFIG. 1, showing operational details thereof;

FIG. 4 is a greatly enlarged, fragmentary, central section of one end ofthe structure of FIG. 1, showing further details thereof;

FIG. 5 is a side elevation in central section of a second embodiment ofthe invention; and

FIG. 6 is a lateral perspective view of a portion of the structure ofFIG. 5.

Briefly stated, the present invention provides a terminal plug for shaderollers of the type characterized by an open tubular end. The terminalplug has a generally cylindrical body portion which is frictionallyinsertable into the tubular end of the roller, and an expandable stopring of resilient material having a normal inside diameter smaller thanthe outside diameter of the cylindrical body but sufiiciently expandableto be telescoped thereover. When the stop ring is not expanded, it seatsabout the body of the plug with sufiicient frictional engagement toresist movement lengthwise of the plug under most normal operatingforces exerted endwise against the roller, and serves to provide anabutment for the tubular end of the roller which limits the insertion ofthe plug thereinto. When the stop ring is circumferentially expanded itis adjustable along the length of the plug to vary the insertion thereofinto the roller tube. The plug has a shoulder structure located at theoutward end thereof opposite the end which is inserted into the roller,and this shoulder has an effective diameter greater than that of theplug body, to prevent the stop ring from being forced over and off fromthe said outward end of the plug. The plug further has means locatedalong its length for engaging at least a portion of the stop ring whenthe same is seated about the plug, to inhibit the movement of the stopring along the said plug under forces which exceed those experiencedunder usual or typical operation, including such forces as are producedby dropping the roller assembly upon its terminal plug end.

Referring now in more detail to the drawings, a first and preferredembodiment 10 of the present terminal plug is illustrated in FIGS. 14inclusive. This embodiment basically includes a generally cylindricalbody portion 12, a resilient stop ring 14 seated about the body 12, anda disc-like cap 16 at the end of the body, including a gudgeon pin ornail 18 of a typical type.

The body portion 12 of this embodiment is preferably a solid woodenmember, and it has a series of buttressshaped annular grooves 20 formedalong its length at the end having the cap '16 and gudgeon 18. As FIG. 2best illustrates, each of the buttress grooves 20 has the edge 21thereof which is positioned nearest the outer or gudgeon pin end of theplug formed substantially normal to the surface of the plug and alsonormal to the longitudinal axis thereof. A ramp-like portion 22 of eachbuttress groove extends rearward from the bottom of the normal edge 21to the outer surface of the plug, and a "brief portion 23 of the plugsurface spaces the ramp portion 22 from the next succeeding normal edge21. In a specific preferred configuration, the normal edge 21 has adepth of about & inch, the length of the ramp 22 is about A; inch, andthe length of the surface portion 23 is about inch.

The stop ring 14 most preferred for use with the body portion 12 justdescribed is a flat, resilient, elastomeric band, as for example ofsynthetic rubber. The width of the band or ring 14 is preferably about Ainch, and the band should have a normal inside diameter which isslightly smaller than the outside diameter of the body portion 12 butthe band should be sufficiently resiliently expandable to be telescopedover the body. Thus, when the band or ring is not expanded it will seatsnugly about the body and the frictional engagement therewith will besufficient to resist movement of the band lengthwise of the plug undernormal operating forces exerted endwise of the roller assembly. That is,when the body portion 12 of the plug is inserted into the open end of anappropriate shade roller, the stop ring 14 seated about the body portionforms an abutment for the tubular end of the roller to limit the degreeof insertion of the plug thereinto, and the frictional engagement of thestop ring and plug will effectively resist a first degree of forceexerted endwise of the roller which might otherwise move the ringrelative to the body and change the effective overall length of theroller.

When the stop ring 14 is intentionaly expanded, it is adjustable alongthe length of the terminal plug, and may be placed in the region of thebuttress grooves 20 formed therein (FIG. 3). In this area, the naturalor inherent resilience of the elastomeric stop ring causes its forwardportion to contract against the ramp edge 22 of a particular buttressgroove, with the forward edge of the band directly abutting the normaledge 21 of that particular groove. Under these circumstances, the stopring or band 14 is effectively indexed in position, and a considerablygreater degree of longitudinal force must be exerted against it in orderto force it out of and over the particular buttress groove with which itis engaged than is the case when the ring is merely seated about thecylindrical portion of the plug body (as seen in FIG. 1). However, sincethe ring is preferably slightly wider than the length of each buttressgroove, it may be easily grasped by the fingers and expanded outwardlyto deliberately move it from one particular groove to another.

The end cap or disc '16 of the terminal plug 10 is preferably a circularsheet metal structure which is stamped to have the cross sectional shapeshown in FIG. 1. Specifically, the outer perimeter or lip 24 of the capis formed to extend away from the gudgeon pin end of the plug and towardthe end thereof which is inserted into the roller tube. Thus, if thestop ring or band 14 is placed or somehow driven to the outer or gudgeonpin end of the plug, as shown in FIG. 4, it comes into contact with ashoulder provided by the extending perimetral portions 24 of the cap.Since the stop ring is preferably a resilient elastomer, if it is placedunder extensive endwise force by the end of a roller tube and drivenagainst the extending shoulder of the end cap, the band will deform bybowing outward over the central area of its width.

The present inventor has determined that if the outer periphery of theend cap is merely vertical, the elastomeric band may become sufficientlydistorted under load to slip over the shoulder and completely off theterminal plug. It is for this reason that the lip portion 24 of the endcap 16 is formed at the angle 26 shown in FIG. 4, which in the mostpreferred form should preferably be approximately 25 degrees. In thisform the angularly extending lip will cradle the edge of the elastomerband and retain it in place about the body of the terminal plug. Thus,the plug will not be driven into the tubular end of the roller by aforce of this nature, and instead the elastomer band will act as a shockabsorber to cushion and dissipate such a force, even though this forcemight be so great as to initially dislodge the stop ring from one ormore of the buttress grooves and move it into contact with the shoulderor lip provided by the end cap.

Due to the manufacturing economies which may presently be achievedthrough the molding of plastic substances, it may be desired to embodythe concepts involved in the terminal plug just discussed in a moldableplastic form. An embodiment 110 of this nature is shown in FIGS. 5 and'6, wherein the cylindrical body portion 112 is tubular in nature, and aterminal cap 116 and gudgeon pin 118 are integral with the body portion112 so as to be moldable as a single unit. A terminal plug of thisnature should preferably be slightly conical in form, i.e., flaredoutwardly slightly toward its inner end, opposite the gudgeon pin.Further, the body portion 112 should have at least one and preferablytwo longitudinal slits or separations 111, so that the actual diameterof the body may be decreased by resiliently contract ing its flared endto insert the plug into a tubular roller. Thus, when the plug isreleased within the roller it will resiliently expand toward its normaldiameter and thereby increase the frictional engagement between plug androller tube. The split and flared molded plastic terminal plug body 112is preferably formed from the plastic known commercially as Delrin, dueto the superior resiliency and plastic memory exhibited by thissubstance.

The stop ring 114 for the terminal plug 110 may also be formed ofmoldable plastic, and preferably has a nominal inside diameter that issmaller than the nominal outside diameter of the plug body. The stopring 114 is circumferentially split (see FIG. 6) so that it may beresiliently expanded to slip over the body 112, where it may be releasedto resiliently grip the surface of the body. It will be noted that whilethe outer surface of the stop ring is fiat, the inner surface is not,and instead has a downwardly-projecting ridge 115 which preferablyextends completely about the inner circumference of the ring. Like theplastic terminal plug body 112, the plastic stop ring 114 is alsopreferably formed from Delrin, for the above-described qualities whichit possesses.

Like the first embodiment 10 of the terminal plug seen previously, theembodiment 110 of FIGS. 5 and 6 is also annularly grooved at the endnear the gudgeon pin. However, when the molded plastic embodiment isused together with the plastic stop ring 114, the annular grooves 120 inthe plastic body need not have the buttress shape which has beenpreviously described, but instead they may have the generally openV-shape illustrated in FIG. 5. This is true since unlike the elastomericstop ring 14, the more rigid plastic stop ring 114 will not contract itsforward edge into the annular groove. Instead, the inner ridge 115 ofthe plastic ring will firmly engage the central portion of each groove,so that the ring is retained against lengthwise movement relative to theplug in an analogous manner. That is to say, the combination of theresilience of the Delrin ring together with its internal ridge 115 actsto retain this stop ring upon the body of a terminal plug somewhat moresecurely than the mere elasticity alone of the resilient rubber ring 14which has no internal ridge, and consequently while the buttress form ofannular groove is extremely useful in connection with a resilient rubberstop ring, the buttress form of annular groove is not strictly necessarywhen a split plastic ring of the aforementioned type, with an internalridge or the equivalent, is used. Nonetheless, the plastic type stopring may be used with the buttress type groovesif desired, although theflat rubber or elastomer stop ring when used with the V-type annulargroove does not give an equivalent performance.

The molded plastic embodiment of the terminal plug, like the woodembodiment previously discussed, also has a shoulder structure at itsgudgeon pin end for preventing the stop ring from being forced over theend and completely off the body of the plug. This shoulder is designated117 in FIG. 5, where it will be noted that unlike the lip 24 of theprevious cap structure 16, the shoulder 117 need not be positioned at anangle relative to the body of the plug, but instead may extend generallyradially or normally thereof. This is true since the more rigid moldedplastic stop ring does not noticeably deform under the application ofendwise force and consequently does not tend to bow out and slip overthe extending shoulder. Thus, all that is required to retain such a stopring on the body of the plug is a radially-extending shoulder for directabutment by the stop ring.

Having now described in detail the structure of two specific embodimentsof the present terminal plug construction, the assembly of each with anassociated shade and roller will likely be entirely apparent. All thatis required is to insert the inner end of the terminal plug opposite thegudgeon pin into the open tubular end of the roller, to the extent thatthe stop ring seated about the surface of the terminal plug comes intoabutting contact with the end of the roller tube. This produces a sturdyand stable roller assembly which may be mounted in a pair of spacedconventional mounting brackets for rotary operation of the shade.

The present form of terminal plug provides several noteworthy anddesirable advantages over the basic removable plug construction,however, which previous construction have failed to do. Firstly, theresilient stop rings may be forcibly expanded and adjusted along thelength of the plug body to vary the insertion of the plug into theroller and thereby change the effective overall length of the rollerassembly. When seated upon the plug, either form of stop ring willmaintain the desired and selected overall length by resisting movementalong the plug under normal operating forces applied endwise of theroller assembly. However, in the area of the annular grooves in theplug, the stop ring is positively indexed at selected incremental lengthadjustments, so that even forces exceeding normal operating forcescannot dislodge the stop ring and change a selected adjustment.

If the roller assembly should be dropped on its gudgeon pin end, asfrequently happens in actual usage, the terminal plug will not be driveninto the roller to render the roller assembly useless, since theengagement of the stop ring by the annular groove will ordinarilyprevent any such occurrence. Further, even if unexpectedly high impactsor other forces are applied to the terminal plug end of the rollerassembly, the plug will still not be driven completely into the rollerdue to the presence of the stop ring and its abutment with the shoulderstnucture at the end of the plug, which effectively serves to preventthe stop ring from being forced over the end of the terminal plug. Insuch an event, either form of stop ring described heretofore helps inabsorbing the unexpectedly large shock due to its resilient nature.Further, such extensive forces will not damage either type stop ringsince the elastomeric ring resiliently deforms itself readily under theshock to dissipate it, while the high compression qualities of theDelrin ring cause it to deform less while nonetheless absorbing theforces exerted upon it.

It is conceivable that after becoming familiar with the principles andthe underlying concepts of the invention set forth heretofore, thoseskilled in the shade roller equipment art will choose to implement theseconcepts in slightly different embodiments or to vary or modify thespecific embodiments which are disclosed hereinabove. All suchembodiments and modifications as incorporate the concepts of theinvention and utilize its fundamental principles are therefore to beconsidered as within the scope of the claims appended herebelow, unlessthese claims by their language specifically state otherwise.

I claim:

1. A terminal plug for shade rollers of the type characterized by anopen tubular end, said plug comprising: a generally cylindrical bodyfrictionally insertable into said tubular end; an expandable stop ringof resilient elastomeric material having a normal inside diametersmaller than the outside diameter of said body but sufiicientlyexpandable to be telescoped thereover; said stop ring when not expandedseating about said plug with sufiicient frictional engagement to resistmovement lengthwise of the plug under a first degree of force exertedendwise of said 7 roller; said stop ring when seated about said plugforming an abutment for the tubular end of the roller to limit theinsertion of said plug thereinto; said stop ring when expanded beingadjustable along the length of said plug; a shoulder structure locatedat the outward end of said plug opposite the end which is inserted intosaid roller; said shoulder having an efiective diameter greater thanthat of said plug body and preventing said stop ring from being forcedover said outward end and off said plug; and a plurality of recessesformed in said body at different positions along the length thereof,each for engaging at least a portion of said stop ring to inhibit themovement thereof along said plug at each of said positions under forcesexceeding said first degree, to thereby index said ring at predeterminedand selectable increments; each of said recesses having an edgepositioned toward said outer plug end, such edges formed normal to saidsurface and normal to the longitudinal axis of the plug; said shoulderstructure including a portion extending radially of said plug body andhaving a lip at its extremity which extends at an acute angle relativeto the body toward that end of said plug which is inserted into saidtubular roller, said portion having an extent sufficient to cause saidlip to engage said stop ring at a point radially outwardly of the meandiameter thereof; said elastomeric ring ,when forced against saidextending lip deforming toward the vertex of said acute angle forpositive retention of the ring upon the plug body under a second degreeof said force exceeding said first degree thereof.

2. The terminal plug defined in claim 1, wherein said shoulder structureis a circular end cap disc, said portion is the central part of saiddisc, and said lip is formed around the peripheral extremity of saiddisc.

3. A terminal plug for shade rollers of the type characterized by anopen tubular end, said plug comprising: a generally cylindrical bodyfrictionally insertable into said tubular end; an expandable stop ringof resilient material having a normal inside diameter smaller than theoutside diameter of said body but sufficiently expandable to betelescoped thereover; said stop ring when not expanded seating aboutsaid plug with sufiicient frictional engagement to resist movementlengthwise of the plug under a first degree of force exerted endwise ofsaid roller; said stop ring when seated about said plug forming anabutment for the tubular end of the roller to limit the insertion ofsaid plug thereinto; said stop ring when exring along said plug at eachof said positions under forces exceeding said first degree and therebyindex said ring at predetermined and selectable increments; said stopring being a split snap ring of molded plastic material havinginternally-projecting portions for engagement by said means.

4. The terminal plug defined in claim 3, wherein said means includes aplurality of recesses formed in the surface of said body, each havingone edge positionedtoward said outer plug end which is formed normal tothe longitudinal axis of the plug.

5. The terminal plug defined in claim 4, wherein said recesses areannular grooves around the circumference of said plug body.

6. The terminal plug defined in claim 3, wherein said body is of moldedplastic material and said shoulder structure is molded integrallytherewith.

7. The terminal plug defined in claim 6, wherein said body is of Delrinplastic, is tubular in form, is flared outwardly toward the end which isinserted into said roller, and is split longitudinally from the saidinserted end so as to be diametrically expandable within said roller.

8. The terminal plug defined in claim 7, wherein said means include aplurality of annular grooves formed circumferentially in the surface ofsaid body and normal to the longitudinal axis thereof.

References Cited UNITED STATES PATENTS 1,687,874 10/1928 McNally 287581,919,114 7/1933 Ley 28758 2,869,541 1/1959 Helrner et al. 287-58 DAVIDJ. WILLIAMOWSKY, Primary Examiner.

PETER M. CAUN, Examiner.

